Well Water in Park County, Colorado
Park County · Population ~18,000 · Aquifer: Alluvial and Sedimentary Rock Aquifers / Fractured Bedrock
Hardness: Variable
Park County's mountain communities sit in South Park — a high-altitude basin with a long mining history. The Fairplay Mining District alone has over 18,000 mining claims on record. That legacy means heavy metals in the soil, tailings piles along waterways, and the potential for mining-related contaminants in groundwater. On top of that, recent PFAS testing found contamination in more than half the wells tested in one community.
Mining Legacy
Mining has been part of Park County since the gold rush. The Fairplay Mining District has 18,081 total claims on record (729 active, 17,352 closed) and at least 8 documented mines. Massive tailings piles line the Middle Fork of the South Platte River.
Mining operations disturb the natural geology and can mobilize heavy metals — lead, arsenic, cadmium, zinc — into groundwater. Tailings piles leach contaminants for decades or centuries after mining stops. Acid mine drainage changes water chemistry in ways that increase metal solubility.
A USGS study of ground-water quality in the vicinity of Fairplay and Alma (2002) specifically examined alluvial and sedimentary-rock aquifers in the area to assess the impact of this mining legacy on water quality.
PFAS: A Modern Contamination
In a more recent development, CDPHE tested 14 private wells in the Burland Ranchettes community in Park County. The results were concerning: PFAS levels exceeded the EPA's proposed maximum contaminant level in 8 of the 14 wells — more than half.
PFAS ("forever chemicals") are synthetic compounds that don't break down in the environment. They've been linked to cancer, immune system effects, and developmental problems. Sources can include firefighting foam, landfills, and industrial discharges.
Private wells are not regulated for PFAS, but the EPA has proposed an MCL of 4 parts per trillion for PFOA and PFOS. If you're in an area with potential PFAS sources, testing is important.
Mountain Well Challenges
Much of Park County is underlain by the same fractured crystalline bedrock found throughout the Front Range mountains. Wells in these formations face the standard mountain challenges: low yield, seasonal variation, and uranium/radon from granitic rocks.
The alluvial aquifers along valley floors (including the area around Fairplay) can produce more water but are more vulnerable to surface contamination — including contamination from mining operations and the Fairplay landfill, which has documented leaching issues.
Testing Recommendations
Park County well owners should test for:
- Heavy metals panel — lead, arsenic, cadmium, zinc, copper, especially if near mining areas
- Radon and uranium — from the granitic geology
- PFAS — if in or near Burland Ranchettes or other areas with potential sources
- Bacteria and nitrates — annual basics
Contact Park County Environmental Health at (719) 836-4267 or CDPHE at (303) 692-3039 for testing guidance. See our testing guide for labs.
Every well is different. Two wells on the same street can produce completely different water. The data on this page reflects documented conditions in the Park County area, but the only way to know what's in your water is to test it.
Sources
- USGS Fact Sheet 2004-3065 — Ground-Water Quality of Alluvial and Sedimentary-Rock Aquifers, Fairplay and Alma, Park County
- CDPHE — Burland Ranchettes PFAS Testing Results
- Park County Environmental Health — Well and Drinking Water Safety
- Mindat.org — Fairplay Mining District Records